Variable Interest Entities - Securitization Activity (Details 4) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Variable Interest Entity (VIE) or Potential VIE, Information Unavailability [Member] | Residential Mortgage [Member]
Securitization activity [Abstract]
Principal securitized	$ 0	$ 0
All cash flows during the period:
Proceeds from new securitizations	0	0
Servicing fees collected	180	226
Purchases of previously transferred financial assets (or the underlying collateral)	59	391
Cash flows received on the interests that continue to be held by the Firm	52	67
Variable Interest Entity (VIE) or Potential VIE, Information Unavailability [Member] | Commercial mortgage [Member]
Securitization activity [Abstract]
Principal securitized	0	1,493
All cash flows during the period:
Proceeds from new securitizations	0	1,558
Servicing fees collected	1	1
Purchases of previously transferred financial assets (or the underlying collateral)	0	0
Cash flows received on the interests that continue to be held by the Firm	43	47
Fair Value, Inputs, Level 2 [Member] | Residential and commercial mortgage securitizations [Member]
All cash flows during the period:
Proceeds from new securitizations		1,300
Fair Value, Inputs, Level 3 [Member] | Residential and commercial mortgage securitizations [Member]
All cash flows during the period:
Proceeds from new securitizations		$ 217